C++:pointers| this pointer

Example:2
Write a C++ program to declare a class named person with attributes as name and age. Take input for details of two person check and print the details of the younger person.
Sol:

#include<iostream>
#include<conio.h>
#include<string.h>
using namespace std;
class person
{
private:
	char name[20];
	int age;
public:
	person(); //default cons
	person(char *n,int a); //para cons
	void read();
	void show();
	person younger(person p);
};
//defa cons
person::person()
{
  name[0]='\0';
  age=0;
}
//para cons
person::person(char *n,int a)
{
  strcpy(name,n);
  age=a;
}
void person::read()
{
  cout<<"Enter name and age ";
  cin>>name>>age;
}
void person::show()
{
  cout<<"name "<<name<<" age "<<age<<endl;
}
person person::younger(person p)
{
  if(age<p.age) //if(this->age<p.age)
  return(*this);
  else
  return(p);
}
/*

*this represents the object using which the member function
is called.

*/
int main()
{
	//person p1("mohit",26);
  	//person p2("sumit",18);
  	person p1,p2;
  	p1.read(); p2.read();
  	person p3;
  	p3=p1.younger(p2);
  	p3.show();
  	getch();
  	return(0);
}

Output:

Enter name and age manan
25
Enter name and age mohan
14
name mohan age 14

Example:3
Declare a class named student with attributes as roll, name and per. Take input for details of 2 students check and print the details of the student higher in the merit list.
(hint: compare per: details of the student with higher per has to be displayed)
Sol:

#include<iostream>
#include<conio.h>
#include<string.h>
using namespace std;
class student
{
private:
	int roll;
	char name[20];
	int per;
public:
	student(); //default cons
	student(int r,char *n,int p); //para cons
	void read();
	void show();
	student higher(student p);
};
//defa cons
student::student()
{
	roll=0;
  	name[0]='\0';
  	per=0;
}
//para cons
student::student(int r,char *n,int p)
{
	roll=r;
  	strcpy(name,n);
  	per=p;
}
void student::read()
{
  cout<<"Enter roll, name and per ";
  cin>>roll>>name>>per;
}
void student::show()
{
  cout<<"roll "<<roll<<" name "<<name<<" per "<<per<<endl;
}
student student::higher(student p)
{
  if(per>p.per) //if(this->per>p.per)
  return(*this);
  else
  return(p);
}
/*

*this represents the object using which the member function
is called.

*/
int main()
{
	//student p1("mohit",26);
  	//student p2("sumit",18);
  	student p1,p2;
  	p1.read(); p2.read();
  	student p3;
  	p3=p1.higher(p2);
  	p3.show();
  	getch();
  	return(0);
}

Output:

Enter roll, name and per 101 aman 98
Enter roll, name and per 102 anmool 85
roll 101 name aman per 98

Example:4
Declare a class named employee with attributes as empno, name and salary ,take input for details of two employees , display the details of the employee getting higher salary.
Sol:

#include<iostream>
#include<conio.h>
#include<string.h>
using namespace std;
class employee
{
private:
	int empno;
	char name[20];
	int sal;
public:
	employee(); //default cons
	employee(int e,char *n,int s); //para cons
	void read();
	void show();
	employee higher(employee p);
};
//defa cons
employee::employee()
{
	empno=0;
  	name[0]='\0';
  	sal=0;
}
//para cons
employee::employee(int e,char *n,int s)
{
	empno=e;
  	strcpy(name,n);
  	sal=s;
}
void employee::read()
{
  cout<<"Enter empno, name and sal ";
  cin>>empno>>name>>sal;
}
void employee::show()
{
  cout<<"empno "<<empno<<" name "<<name<<" sal "<<sal<<endl;
}
employee employee::higher(employee p)
{
  if(sal>p.sal) //if(this->sal>p.sal)
  return(*this);
  else
  return(p);
}
/*

*this represents the object using which the member function
is called.

*/
int main()
{
	//employee p1("mohit",26);
  	//employee p2("sumit",18);
  	employee p1,p2;
  	p1.read(); p2.read();
  	employee p3;
  	p3=p1.higher(p2);
  	p3.show();
  	getch();
  	return(0);
}

Output:

Enter empno, name and sal 101
gopal
45000
Enter empno, name and sal 102
mohan
65000
empno 102 name mohan sal 65000